Fix C++11 build error related to VersionNumber.cxx
The following error is reported when building SMTK on system providing C++11 prior to the CWG 1270 revision:
/path/to/smtk/smtk/common/VersionNumber.cxx:22:34: error: array must be initialized with a brace-enclosed initializer
: std::array<int, 3>{ -1, 0, 0 }
^
References:
- https://en.cppreference.com/w/cpp/container/array#Example
- smtk commit 93bb4716 introducing the "regression"